FotS

The MMBasic INKEY$ function is used within a running program to detect a character from the console.This is generally the ASCII value of that keys character. VT100 terminals generate a number of characters to signal the function keys and other functions like Page Up,Page Down,End and Home. The INKEY$ function in Picomites and latest releases of ARMmite F4 and ARMmite H7 resolve these to a single byte as shown in the table below. The table is based on codes generated by Teraterm but other VT100 emulations are similiar.

There are two methods
char$=INKEY$
char$=Input$(100,#0)

Pressing the CNTRL key on the keyboard (directly connected or via VT100) with a normal key will result on the code for that key being masked so that only the bottom five bits (B4-B0) are used. This results in mapping those combinations to the lower non printable ascii characters 00-1F i.e. 0-31 e.g. CNTRL+C gives 3.

The CNTRL modifier is useful if the terminal being used has no function keys to allow the use of the editor.

This table shows the mapping of CNTRL + key combinations to MMBasic Editor functions.

The SUB below can be called from the main DO:LOOP to interact with a running program from an attached terminal.This can be useful for debugging and developing a hardware interface that requires the program to be running.

SUB ReadConsole

   local char$
   ' j=LOC(#0)
   'char$= INPUT$(100,#0)
   char$=INKEY$
   IF char$<>"" then
     if char$=chr$(145)  then  print "F1"  'F1 VT100
     if char$=chr$(146)  then  print "F2"  'F2 VT100
     if char$=chr$(147)  then  print "F3"  'F3 VT100
     '
     '
     if char$=chr$(156)  then  print "F12"  'F12 VT100
    
     if char$=chr$(127) or mid$(char$,2)="[3~" then  'DEL
               
     end if
     if char$=chr$(128) or mid$(char$,2)="[A" then  'up arrow VT100
                  
     end if
     if char$=chr$(129) or mid$(char$,2)="[B" then  'down arrow
           
     end if
     if char$=chr$(131) or char$=chr$(4) or mid$(char$,2)="[C" then 'right arrow VT100 MMEdit
              
     end if
     if char$=chr$(130) or char$=chr$(19)or mid$(char$,2)="[D"  then  'left arrow VT100 VT100 MMEdit
     
          
     end if
     if char$=chr$(132) or mid$(char$,2)="[2~" then  'INS
       
             
     end if
     if char$=chr$(133) then
        print "133"
          
     end if
     if char$=chr$(134) or mid$(char$,2)="[1~" then 'home
        
           
     end if
     if char$=chr$(135) or mid$(char$,2)="[4~" then  'end
        
            
     end if
     if char$=chr$(136) or mid$(char$,2)="[5~" then  'PgUp VT100
         
         
     end if
     if char$=chr$(137) or mid$(char$,2)="[6~" then  'Pgdn VT100
        
             
     end if
     if char$=chr$(138) then
        print "138"
          
     end if
     if char$=chr$(139) then
        print "ALT"
            
     end if
     if char$=chr$(140) then
        print "140"
         
     end if

   

   END IF
END SUB